New Non Starter

[Jaydee]

Hi Dexta lovers, by way of an introduction, I have a 58 dexta which I have now owned for 5 years. She was bought with the intention of restoring to her former glory, when I both found the time and learned enough to do the work. Unfortunately, so far, I have found neither!!
I have managed to keep her happily working (too hard really for a girl of her age, but she rarely complains ) with help from lurking on this forum, so thankyou to all those who have unknowingly already helped me.
So now to my latest problem, I have searched the old forum but can't seem to find the right info.
We were happily topping the grass in 1 field, as usual without missing a beat, when we moved to the 2nd, the revs picked up, but not as smooth as normal, when the PTO was engaged, the revs died away untill clutch engaged again, then she picked up again but seemed to be missing. No problem I thought, had this before, blockage in the fuel line , drove back to the yard and dutifully cleaned out the guaze in her tank and checked all the fuel lines, bled out air and away she went again, sounding fine. On the way back to the field (slight uphill) she just didn't have the puff, and sounded like she would stall. Having run out of time, drove her back to the yard and parked up. On returning a couple of days later, I checked out the fuel lines again, just to make sure, then she refused to start. Checking on here, I found out that the pump for the heater may not be working correctly, took out the jet, and sure enough it was not getting much fuel through. Having cleaned it, it now gives a good spray, and I can hear the fuel ignite in the manifold when the pump is pressed, but she still will not start She is turning over happily, and white/grey smoke is coming from the exhaust, but she just won't fire. I don't wan't to try easy start, as she's never needed it before.
So, sorry for the long first post but hopefully one of you experts may be able to suggest what to look at next. But, please be gentle!! my mechanical knowledge has mostly been learned from reading this forum
Thanks in advance.
Jaydee

[Brian]

Wecome to the board Jaydee.

Starting at the first basic point, it sounds like you may have had a fuel blockage. Have you replaced the fuel filter as well as cleaned the tank filter?

Since having the tank filter out, have you bled the system? A diesel engine needs to have the air in the system cleared before it will start. The pump cannot compress air so you need to bleed the air from the filter and from the injection pump. There are bleed screws on the top of the fuel filter and one on the side of the pump just under the place where the injector pipes fit to it. Use the hand primer on the fuel lift pump to ensure air free diesel flows from these points. If the hand primer does not seem to work, turn the engine over a little way and try again. Do not overtighten the bleed screws as they are fragile.

If she still won't fire, slacken all the injector pipes at the injectors. They need to be just loose enough for diesel to leak from them. Crank the engine over, watch for diesel from the loose connections and tighten them one at a time with the engine cranking.

If she does not fire after this report back.

[Jaydee]

Thanks for the swift reply Brian.

I didn't change the filter as I didn't have one. (I think I've seen the part No elswhere on this site, I will order one ASAP), but did remove some horrible looking sludge from the filter housing.

I thought I had bled it sufficiently, but had only done it at the filter housing, so thankyou for the clear instructions, I'll give it a go and report back.

[Brian]

If you have gunge in the filter housing it is 98% certain the filter is blocked. You could try it without a filter as a test but don't spend days running without it. A new one is your immediate mission

[Jaydee]

Thanks Brian, Have followed your instructions this evening and away she went .

However I am feeling more than slightly embarrased that it was as simple as bleeding the lines as I thought I'd done that!

She ran up to PTO revs and when I engaged the topper, no problems. Just have to wait for all this rain to stop to give her a working test.

I see your point about the filter and will order one up tomorrow.

Thanks again for your help.

[Brian]

Glad to be of help.

When in difficulty, always start with the simple things. (Not that I always stick to that myself).

Once, many years ago, we had a call to a farmer with a gearbox problem on a Massey Harris 780 combine. It would go into gear but not move. My boss had already got our jobs for the day lined up so it wqs late afternoon when I got to the farm to find the combine, in the field, with the gearbox stripped out and laid, in pieces, on sacks, and the farmer scratching his head saying he could find nothing wrong with it.

I too could see no broken gears or bearings but when I picked up the gear selector I found the broken roll pin that connected the lever onto the selector shaft. This would have been perfectly accessible without dismantling any part of the combine. The pin allowed the gear lever to move into position but it did not move the selector.

A 5 minute job which would have cost pence had stopped the combine all day and the farmer had a big bill for reassembling the combine.

[Mark]

Welcome to the board Jaydee,
My Dexta did this same thing and we had similar problems, only I also had something in my fuel tap. Glad you got her running.

[Jerry Coles]

Sorry Brian to be a bit pedantic but the air can be compressed and therefore absorbs the fuel pulse from the injector pump. Thats why the air must be bled out so that only the liquid (Diesel) which cannot be compressed is in the system.The pulse from the pump therefore transmits up to the fuel at the injector and the injector then sprays the fuel out of the nozzle.

Jerry near Bath

[Paul]